Synergistic effect of Ti(OBu)4 and annealing regime on the structure, morphology and photoelectrochemical response of α-Fe2O3 photoanode

Ti-modified α-Fe2O3 photoanodes are prepared by one-step hydrothermal method with Ti(OBu)4 solution as the Ti precursor followed by annealing treatment. Through the synergistic effect of small amount of Ti(OBu)4 and high annealing temperature, the 0.3TiFe-H photoanode has a significant enhanced photocurrent response as 1.31 mA cm−2, which is almost 33 times than that of the Bare-Fe photoanode as 0.04 mA cm−2 and 3 times than that of the Bare-Fe-H photoanode as 0.46 mA cm−2. The enhanced photoelectrochemical response is mainly attributed to the increased bulk charge separation caused by excellent conductivity, and surface charge injection caused by synergistic effect of decreased resistance and increased capacitance at the surface. This work provides an indepth understanding of the effect of Ti(OBu)4 and annealing regime on morphology, crystalline structure and photoelectrochemical performance of Ti-modified hematite photoanode via systematical characterization with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis spectra, X-ray diffractometry (XRD), X-ray photoelectron spectra (XPS), and photoelectrical measurements.